Patent GB-118838-A (GB)
Title: Improvements in Mechanical Stokers.
IPC: F23K3/10
Filed: 1918-06-25
Abstract: 118,838. Westinghouse Electric & Manufacturing Co., (Assignees of Miller, C. F.). Aug. 31, 1917, [Convention date] Stoking; fire-bars and grates.-A mechanical furnace comprises a hopper with reciprocating fuel-feeders, hollow air-cooled inclined fire-bars alternately fixed and movable, and an automatically-operated ash-dumping plate or grate the movements of which are controllable. Fuel is fed from a hopper 17 to a " retort " 10 by reciprocating feeders 11, anrl thence to the hollow fire-bars 12, 12<1> and to the dumping-grate 36. The apparatus is mounted on a structure divided into two air chambers 25, 25<a>, through which air from a trunk 27 passes to the fire,-bars and to the air-supplying box 18, and also past a damper 69 to the dumping-grate 36. The apparatus is driven by a motor 47, connecting-rod 48, and lever 49. which oscillate a shaft 38. Toothed sectors 11' on this shaft reciprocate the feeders 11, and levers 34, 34<1> and a link 34" reciprocate the fire-bars 12, between which ore the fixed bars 12<1>. On the shaft 38 is also a lever 39 connected by a variable link 61, 63, Fig. 2, to the bell-crank 41, which, by means of the links 42, 43, rack 44, pinion 45, lever 45<a>, and link 46, operate as desired the dumping-grate 36. The grate is supported on fittings 21<a>, 30 at the upper ends of pillars or the like 21, 31 mounted upon a framing 22, 22<a>. The lower ends of the movable bars are supported directly by a bar 32, preferably made in short sections. This bar has cylindrical top and bottom flanges and a perforated web through which air passes into the accumulation of ash nt the rear of the grate, and oscillates as the fire-bars 12 are reciprocated by the lever 34. The fixed bars 12<1> are supported by the bars 21a and the front edge of the air-supply fitting 24, the lugs 12<a>, 12b bear. ing against these respective parts and preventing the bars from moving. The front ends of the moving bars 12 are connected by hook or " hinge " engagements with an apron 35, preferably made in sections, which breaks up the fuel as it enters the "retort" 10. The mechanism for varying the throw of the dumping-grate 36 comprises a hand-wheel 59, Fig. 2, and worm and worm-sector gearing 52, 53 which adjusts, by means of levers 54, 56 and links 55, 57, the position on the rod 61, 62 of a sleeve 51. When this is moved to a position lower than that shown, the oscillation of the shaft 38 and the rod 61, 62 causes the sleeve 51 to engage with and separate spring-pressed dogs 63 which connect the sleeve 62 to the rod 61, so that the rod 61 continues its upward movement without affecting the part 41 and the dumping-grate connected to it. A stop 64 engages .with the arm 54 as the dogs 63 release the rod 61, and prevents the dumping-grate 36 from falling. The arm 45<a>, Fig. 1, is fitted upon its shaft in such a position that the movement of the operating-gear causes it to rise before beginning its downward movement, thus crushing the clinkers &c. against the wall 38. In the lowest position of the sleeve 51, the grate 36 is retained in its up-raised position and does not move. A stop 66 on the rod 43 prevents the grate 36 from moving up too far. A damper 69, operated by rods &c. 70, is adjustable to control the flow of air through the fittings 30 and thence through the dumping-grate 36. The grate 36 may be in sections independently operated.